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// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
static volatile int sigusr1_received = 0;
static void sigusr1_handler(int signum)
{
sigusr1_received++;
}
static void test_send_signal_common(struct perf_event_attr *attr,
int prog_type,
const char *test_name)
{
int err = -1, pmu_fd, prog_fd, info_map_fd, status_map_fd;
const char *file = "./test_send_signal_kern.o";
struct bpf_object *obj = NULL;
int pipe_c2p[2], pipe_p2c[2];
__u32 key = 0, duration = 0;
char buf[256];
pid_t pid;
__u64 val;
if (CHECK(pipe(pipe_c2p), test_name,
"pipe pipe_c2p error: %s\n", strerror(errno)))
return;
if (CHECK(pipe(pipe_p2c), test_name,
"pipe pipe_p2c error: %s\n", strerror(errno))) {
close(pipe_c2p[0]);
close(pipe_c2p[1]);
return;
}
pid = fork();
if (CHECK(pid < 0, test_name, "fork error: %s\n", strerror(errno))) {
close(pipe_c2p[0]);
close(pipe_c2p[1]);
close(pipe_p2c[0]);
close(pipe_p2c[1]);
return;
}
if (pid == 0) {
/* install signal handler and notify parent */
signal(SIGUSR1, sigusr1_handler);
close(pipe_c2p[0]); /* close read */
close(pipe_p2c[1]); /* close write */
/* notify parent signal handler is installed */
write(pipe_c2p[1], buf, 1);
/* make sure parent enabled bpf program to send_signal */
read(pipe_p2c[0], buf, 1);
/* wait a little for signal handler */
sleep(1);
if (sigusr1_received)
write(pipe_c2p[1], "2", 1);
else
write(pipe_c2p[1], "0", 1);
/* wait for parent notification and exit */
read(pipe_p2c[0], buf, 1);
close(pipe_c2p[1]);
close(pipe_p2c[0]);
exit(0);
}
close(pipe_c2p[1]); /* close write */
close(pipe_p2c[0]); /* close read */
err = bpf_prog_load(file, prog_type, &obj, &prog_fd);
if (CHECK(err < 0, test_name, "bpf_prog_load error: %s\n",
strerror(errno)))
goto prog_load_failure;
pmu_fd = syscall(__NR_perf_event_open, attr, pid, -1,
-1 /* group id */, 0 /* flags */);
if (CHECK(pmu_fd < 0, test_name, "perf_event_open error: %s\n",
strerror(errno))) {
err = -1;
goto close_prog;
}
err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
if (CHECK(err < 0, test_name, "ioctl perf_event_ioc_enable error: %s\n",
strerror(errno)))
goto disable_pmu;
err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
if (CHECK(err < 0, test_name, "ioctl perf_event_ioc_set_bpf error: %s\n",
strerror(errno)))
goto disable_pmu;
err = -1;
info_map_fd = bpf_object__find_map_fd_by_name(obj, "info_map");
if (CHECK(info_map_fd < 0, test_name, "find map %s error\n", "info_map"))
goto disable_pmu;
status_map_fd = bpf_object__find_map_fd_by_name(obj, "status_map");
if (CHECK(status_map_fd < 0, test_name, "find map %s error\n", "status_map"))
goto disable_pmu;
/* wait until child signal handler installed */
read(pipe_c2p[0], buf, 1);
/* trigger the bpf send_signal */
key = 0;
val = (((__u64)(SIGUSR1)) << 32) | pid;
bpf_map_update_elem(info_map_fd, &key, &val, 0);
/* notify child that bpf program can send_signal now */
write(pipe_p2c[1], buf, 1);
/* wait for result */
err = read(pipe_c2p[0], buf, 1);
if (CHECK(err < 0, test_name, "reading pipe error: %s\n", strerror(errno)))
goto disable_pmu;
if (CHECK(err == 0, test_name, "reading pipe error: size 0\n")) {
err = -1;
goto disable_pmu;
}
CHECK(buf[0] != '2', test_name, "incorrect result\n");
/* notify child safe to exit */
write(pipe_p2c[1], buf, 1);
disable_pmu:
close(pmu_fd);
close_prog:
bpf_object__close(obj);
prog_load_failure:
close(pipe_c2p[0]);
close(pipe_p2c[1]);
wait(NULL);
}
static void test_send_signal_tracepoint(void)
{
const char *id_path = "/sys/kernel/debug/tracing/events/syscalls/sys_enter_nanosleep/id";
struct perf_event_attr attr = {
.type = PERF_TYPE_TRACEPOINT,
.sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CALLCHAIN,
.sample_period = 1,
.wakeup_events = 1,
};
__u32 duration = 0;
int bytes, efd;
char buf[256];
efd = open(id_path, O_RDONLY, 0);
if (CHECK(efd < 0, "tracepoint",
"open syscalls/sys_enter_nanosleep/id failure: %s\n",
strerror(errno)))
return;
bytes = read(efd, buf, sizeof(buf));
close(efd);
if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "tracepoint",
"read syscalls/sys_enter_nanosleep/id failure: %s\n",
strerror(errno)))
return;
attr.config = strtol(buf, NULL, 0);
test_send_signal_common(&attr, BPF_PROG_TYPE_TRACEPOINT, "tracepoint");
}
static void test_send_signal_perf(void)
{
struct perf_event_attr attr = {
.sample_period = 1,
.type = PERF_TYPE_SOFTWARE,
.config = PERF_COUNT_SW_CPU_CLOCK,
};
test_send_signal_common(&attr, BPF_PROG_TYPE_PERF_EVENT,
"perf_sw_event");
}
static void test_send_signal_nmi(void)
{
struct perf_event_attr attr = {
.sample_freq = 50,
.freq = 1,
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
};
int pmu_fd;
/* Some setups (e.g. virtual machines) might run with hardware
* perf events disabled. If this is the case, skip this test.
*/
pmu_fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */,
-1 /* cpu */, -1 /* group_fd */, 0 /* flags */);
if (pmu_fd == -1) {
if (errno == ENOENT) {
printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n",
__func__);
test__skip();
return;
}
/* Let the test fail with a more informative message */
} else {
close(pmu_fd);
}
test_send_signal_common(&attr, BPF_PROG_TYPE_PERF_EVENT,
"perf_hw_event");
}
void test_send_signal(void)
{
if (test__start_subtest("send_signal_tracepoint"))
test_send_signal_tracepoint();
if (test__start_subtest("send_signal_perf"))
test_send_signal_perf();
if (test__start_subtest("send_signal_nmi"))
test_send_signal_nmi();
}
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